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J. Agric. Food Chem. 2008, 56, 1734–1739
Effects of Water-Soluble Carbohydrate Concentrate from Chinese Jujube on Different Intestinal and Fecal Indices YA-LING HUANG,† GOW-CHIN YEN,† FUU SHEU,§
AND
CHI-FAI CHAU*,†
Department of Food Science and Biotechnology, National Chung Hsing University, 250 Kuokuang Road, Taichung 40227, Taiwan, and Department of Horticulture, National Taiwan University, Taipei 10673, Taiwan
This study was to investigate the effects of water-soluble carbohydrate concentrate (WSCC) prepared from Chinese jujube (Zizyphus jujuba) on different intestinal and fecal indices in a hamster model. WSCC contained carbohydrates (771 g kg-1 of WSCC) including glucose, fructose, pectin polysaccharide, and hemicellulose. The administration of WSCC (5.0 and 15 g kg-1 of diet) effectively (P < 0.05) shortened gastrointestinal transit time (by 34.2–57.3%), reduced cecal ammonia (by 58.1–60.3%), elevated total short-chain fatty acid concentrations in cecum (3–4-fold), increased fecal moisture (147–170%), reduced daily fecal ammonia output (by 31.9–75.8%), and decreased the activities of β-D-glucuronidase (by 73.0–73.8%), β-D-glucosidase (by 58.2–85.7%), mucinase (by 46.2–72.6%), and urease (by 31.9–48.7%) in feces. This study suggested that adequate consumption of jujube WSCC (at least 5.0 g kg-1 of diet or 40 mg day-1) might exert favorable effects on improving the gastrointestinal milieu and reducing the exposure of intestinal mucosa to toxic ammonia and other detrimental compounds. KEYWORDS: Bacterial enzyme; carbohydrate; Chinese jujube; Zizyphus jujuba; intestinal function; shortchain fatty acid
INTRODUCTION
Some studies have demonstrated that the consumption of certain carbohydrates such as polysaccharides and oligosaccharides might help influence the growth and enzyme activities of some intestinal microflora, support normal intestinal structure, and decrease the risk of gastrointestinal disease (1–3). Inside the hindgut and feces, the activities of some bacterial enzymes (e.g., β-glucosidase, β-glucosidase, mucinase, and urease) catalyze a broad range of metabolic transformations, resulting in the production of toxic, carcinogenic, or mutagenic effects in the colon (4–6). The measurement of these bacterial enzymes in the intestinal lumen and feces might hence be used as a biomarker to evaluate the change in intestinal function, health, and integrity. Short-chain fatty acids (SCFAs) (e.g., acetate, propionate, and butyrate) play an important role in maintaining the health and integrity of the colonic epithelium (7) and, hence, provide a useful clue to reflect the changes in intestinal environment and health. Chinese jujube (Zizyphus jujuba) is a popular fruit native to China or Syria and is widely distributed in the warmer parts of Europe, southern Asia, Africa, and Australia. In addition to their culinary uses, dried Chinese jujubes have traditionally been used * Corresponding author (telephone +886-4-22852420; fax 886-422876211; e-mail chaucf@ nchu.edu.tw). † National Chung Hsing University. § National Taiwan University.
for medicinal purposes, with the fruit being made into paste, soup, puree, syrup, and confection that were supposed to be consumed for digestion enhancement and general health maintenance (8). Depending on different recipes and dietary purposes, the general method of consumption is to cook ∼50 g of dried jujubes (∼20 pieces of whole fruit, 2–2.5 cm in length) in water to prepare a hot soup or drink. Our preliminary study has revealed that the dried extract (∼82.4 g kg-1 of dried jujube, DW) obtained from the jujubes was high in water-soluble carbohydrate (∼77% by weight on a moisture-free basis). As limited scientific literature about the physiological effects of jujube extract on the intestinal function and health is available, further studies on the jujube extract would be useful to clarify its physiological benefits and also provide a clue to substantiate its traditional dietary and therapeutic uses. The objective of this in vivo studywas to investigate the effects of the water-soluble carbohydrate concentrate (WSCC) prepared from Chinese jujubes on the activities of some colonic bacterial enzymes, SCFA concentrations in the cecal content, and also certain biochemical parameters in the intestinal tract and feces. On the scientific basis, the potential effects of the jujube extract on maintaining or improving the gastrointestinal milieu were discussed. MATERIALS AND METHODS Preparation of Jujube WSCC. Dried Chinese jujube sample was obtained from Ko Da Pharmaceutical Co., Ltd. (Taiwan). The seed and
10.1021/jf072664z CCC: $40.75 2008 American Chemical Society Published on Web 02/06/2008
Effects of Jujube Carbohydrate on Intestinal and Fecal Indices
J. Agric. Food Chem., Vol. 56, No. 5, 2008
Table 1. Proximate Compositiona of the Jujube WSCCb proximate composition
g kg
-1
Table 4. Effect of the Jujube WSCC on the Gastrointestinal Transit Time, Fecal Moisture Content, and Fecal Dry Weight
of WSCC (dry wt) 47.6 ( 6.5 37.7 ( 0.1 201 ( 22.8
protein ash polysaccharide fraction disaccharide fraction sucrose monosaccharide fraction glucose fructose total crude saponin total polyphenols
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trc 274 ( 2.3 296 ( 20.4 46.0 ( 4.5 32.0 ( 1.4
diet groupa
gastrointestinal transit timeb (h)
fecal dry wtb (g day-1)
fecal moisture contentb (g kg-1 of feces)
control low dose medium dose high dose
10.1 ( 0.07w 9.34 ( 0.20w 6.65 ( 0.39x 4.31 ( 0.01y
0.83 ( 0.12w 1.00 ( 0.12w 0.88 ( 0.06w 0.99 ( 0.05w
269 ( 22.5w 280 ( 47.5w 394 ( 26.9y 458 ( 28.2z
a
Means ( SD of triplicate determinations. b Moisture content of the WSCC was 305 ( 4.0 g kg-1 WSCC. A small amount of unknown fraction in the extract (∼65.7 g kg-1 WSCC) refers to some certain oligosaccharides and bioactive compounds. c Trace amount (
